Removal of wax from hydrocarbon oils



for example,

. bility Patented Mar. '19, 1929.

UNITED STATES ROBERT S. LANE, OF WOOD RIVER, ILLINOIS,

ASSIGNOR TO STANDARD OIL COMPANY,

OF WHI'IING, INDIAN A, A CORPORATION OF INDIANA.

REMOVAL OF WAX FROM'HYDROCARBON OILS.

No Drawing.

This invention relates to the separation of petrolatum from Wax bearing oils, particularly residues, such as cylinder stocks, and lubricating distillates.

According to the present invention the wax bearing oil to be treated is thoroughly mixed with a diluent liquid comprising a mixture of naphtha, butyl alcohol and acetone, and subjected to a low temperature whereupon the petrolatum or wax is 're-' moved by settling or by centrifuging orin other suitable manner. In some cases the naphtha may be omitted and a diluent consisting of butyl alcohol and acetone employed The diluent mixture may suitably contam from 35 to 60% of naphtha, from 25 to 35% of butanol and from 12 to 35% of acetone. Thus, the following mixtures have been found suitable for the present invention.

Example 1, naphtha 50%; butanol 30%; acetone Example 2, acetone 13%.

Example 3, acetone 27%.

Example 4, acetone 33%.

In carrying out the invention the diluent mixture is mixed'with the oil to be treated,

a cylinder stock, in the proportion of from 50 to 75% of the diluent to 50 to of the oil. slowly settled and cooled to a temperature of 20 F. or lower. The wax settled out, may be removed by gravity, or if desired centrifuging. The wax-free oil is separately withdrawn, the diluent removed by distillation and the oil thereafter is finished in any suitable manner. Owing to the soluof water in acetone, it is preferred to distill the solvent off with either closed coil steam or by circulating hotoil through coils in the still until a large percentage of the solvents have been removed, that is, until the butanol and acetone have been almost entirely distilled. Thereafter open steam may be introduced to remove the heavier naphtha 58% butanol 29 naphtha i4%; butanol29%;

naphtha 37 butanol The mixture is then 4 Application filed January 2, 1926. Serial No. 79,004.

ends of the naphtha and to secure an oil of the desired flash point.

As an example of the operation of the proccss, a cylinder stock obtained by the reduction of mid-continent crude, having a gravity of 21 A. P. I. and a chill point of 75 F. was mixed with a diluent such as that described in Example No. 1 above, in the proportion of 25 parts of the oil to 7 5 parts of the diluent. cooled and settled at 10 F., the petrolatum free oil withdrawn, and upon reduction to a gravity of 213 A. P. I. and a flash point of 520 F., showed a chill point of 15 F.

Although the present invention has been described in connection with the details of a specific embodiment thereof, it is not. in-

tended that such details shall be regarded as limitations upon the scope of the invention, except in so far as included in the accompanying claims.

I claim: 7

1. The method of removing petrolatum from oil comprising the admixture of the oil with a diluent containing butanol and acetone, cooling the mixture and separating the wax from the diluent oil.

2. The method of removing petrolatum from oil comprising the admixture of the oil with a diluent containing naphtha, butanol and acetone, cooling the mixture and separating the wax from the dilutod oil by the difference in their specific gravities. I

3. The method of removing petrolatum from oil comprising the admixture of the oil with a diluent containing to 60% of The mixture was. 

